EP0572753A1 - Loom with sectional warp beams - Google Patents

Abstract

Each of the sectional warp beams (1 and 2) is assigned a measuring device (31 and 32) for recording the length of a particular length portion of at least one of the warp threads (10) which runs off from the respective sectional warp beam (1 or 2) during a warp-thread feed. The measuring devices (31 and 32) can each contain a measuring roller (37) which can be pressed against a number of warp threads (10), for example against the circumference of the wound sectional warp beam (1 or 2), and can be driven by these during the warp-thread feed and via which a corresponding control signal can be transmitted to a control device (25). The rotational speeds of the sectional warp beams (1 and 2) can be influenced via the control device (25) in dependence on these control signals, with the effect of keeping constant a predetermined length of the respective warp-thread feed. The invention is suitable especially for the weaving off of sectional warp beams (1 and 2) having different winding diameters (D1 and D2), whilst a cloth appearance which is homogeneous of the entire weaving width of the loom can be achieved. <IMAGE>

Description

The invention relates to a weaving machine with at least two partial warp beams and a tensioning beam for guiding warp threads running from the partial warp beams, each of the partial warp beams being coupled to an individually controllable warp let-off device and sensing elements for detecting the tension of the warp threads and a control device for individually adjusting the speed of the partial warp beams are provided.

In a weaving machine of the type mentioned, which is known from EP-PS 0 136 389 (T.632), the sensing elements intended for detecting the warp thread tension are arranged between a stationary rod-shaped deflecting element for the warp threads and the tensioning beam connected downstream of the part warp beams in the running direction of the warp threads in this embodiment, it is pivotably arranged on a supporting beam parallel to the axis of the partial warp beams. When two or more partial warp beams are weaved, these are driven individually at a speed depending on control signals from the sensing elements that all warp threads running from the partial warp beams have essentially the same warp thread tensions. Each occurring difference in the warp thread tensions in the ones running from the partial warp beams is corresponding Warp threads immediately compensated for by a corresponding correction of the speed of the partial warp beams.

In another known weaving machine, the tensioning beam is mounted in bearings movable transversely to its axis, which allow the tensioning beam to be inclined with respect to the axis of the warp beam, with corresponding sensing elements assigned to the ends of the tensioning beam compensating for different warp thread tensions in the warp threads running off the partial warp beams can be achieved (DE-PS 27 58 816 or US-PS 4,262,706 / T.500).

It has been shown that the known regulation of the speeds of the partial warp beams, which is dependent solely on the tension of the warp threads, is not sufficient in all cases to achieve the same fabric appearance in each of the woven webs woven from the partial warp beams and thus a constant fabric quality over the entire weaving width . In particular in the case of looms with high weft insertion rates and / or with different diameters of the part warp beams, it can happen that, despite keeping the warp thread tension in the part warp webs constant, the part warp beams are not weaved at the same time, fabric webs of different lengths are produced and / or when weaving together of several part warp beams Warp threads form an inhomogeneous fabric image in the partial fabric webs, whereby a seam between the partial fabric webs or a fold can be formed due to uneven lengths of the partial fabric webs.

The invention has for its object to provide a weaving machine, in particular improved in this regard, with a warp let-off device, by means of which the production of a fabric even when using part warp beams with different winding diameters, for example when processing warp thread stocks on partly weaved part warp beams for recycling residual chains or of several fabric webs with a homogeneous product image over the entire weaving width of the loom is guaranteed.

This object is achieved according to the invention by the features specified in the characterizing part of claim 1.

The measuring devices provided according to the invention, which measure the length of the respective warp feed, make it possible to achieve a warp feed that is independent of the respective winding diameters of the partial warp beams and constant over the entire weaving width of the weaving machine, which enables the warp threads running from the individual partial warp beams to be woven together without the shortcomings described above, such as they can occur in previous versions with a warp let-off device regulated exclusively as a function of the warp thread tension. The control of the warp let-off device according to the invention permits both the production of a fabric web that is undivided over the weaving width of the weaving machine and the production of partial fabric webs, the widths of which in the usual way correspond to the widths of the partial warp beams, or of partial fabric webs which, by subsequently separating the undivided fabric web, also widths that are independent of the widths of the partial warp beams can be implemented.

The control of the warp let-off device according to the invention at the same time allows the warp thread consumption to be influenced when processing weft threads, which, for example due to different stretching or relaxation at the end of the weft insertion process, can have different thicknesses before the change of subject, ie before the warp threads are integrated. If the warp let-off is controlled exclusively as a function of the warp thread tension, different wrap threads of different lengths or correspondingly different warp thread feeds can occur when the weft threads are wound, which can lead to a correspondingly different weft thread density and thus to visible irregularities in the fabric. Through the inventive, depending on a predetermined Warp thread consumption controllable warp let-off device also avoids such shortcomings of previous designs.

Embodiments of the invention are specified in the dependent claims.

Fig.1 eine

erfindungsgemäss ausgebildete Webmaschine in einer vereinfachten Ansicht, von der Kettseite her gesehen,

Fig.2

einen Teilschnitt der Webmaschine entsprechend der Linie II - II in Fig.1, in einer grösseren Darstellung,

Fig.3 und 4

entsprechende Teilschnitte weiterer Webmaschinen, je in einer abgewandelten Ausführungsform,

Fig.5

eine Einzelheit einer Webmaschine in einer weiteren abgewandelten Ausführungsform, in einer grösseren Darstellung, und

Fig. 6

ein Diagramm mit bei einer Ausführung gemäss Fig. 5 erzeugten Steuersignalen.

Further details emerge from the following description of exemplary embodiments of the invention shown schematically in the drawing, in conjunction with the claims. Show it:

Fig.1 a

Weaving machine designed according to the invention in a simplified view, seen from the warp side,

Fig. 2

1 shows a partial section of the weaving machine according to the line II - II in FIG. 1, in a larger representation,

Fig. 3 and 4

corresponding partial sections of further weaving machines, each in a modified embodiment,

Fig. 5

a detail of a weaving machine in a further modified embodiment, in a larger representation, and

Fig. 6

a diagram with control signals generated in an embodiment according to FIG. 5.

1 contains two part warp beams 1 and 2, which are arranged between two cheek parts 3 and 4 of a machine frame and which have different part weaving widths B1 and B2 and different winding diameters D1 and D2. The warp beams 1 and 2 are each stored in a side bearing (not shown) connected to the cheek part 3 or 4 and in a corresponding middle bearing arranged on a central support part 5 and each via a gear 6 with a separately controllable drive motor 7 or 8 connected. The Sub-warp beams 1 and 2 are wound with warp threads 10, which are processed as sub-chains 11 and 12 according to the arrows 13 from the sub-warp beams 1 and 2 each to a warp beam tube 9, from which they run in a path 10 'shown in dashed lines. The warp threads 10 are guided against the goods tree via a rod-shaped deflecting element 14 which is arranged in a stationary manner on the machine frame and a tensioning beam 15 arranged downstream thereof in the warp running direction (arrows 13) and via further parts of the weaving machine, not shown, such as heald frames, weaving reeds, etc. The deflection element 14 and the tensioning beam 15 extend over the entire weaving width B of the weaving machine, which is given by the respective, adjustable distance between the two outer warp beam discs 16 of the sub-warp beams 1 and 2.

The tensioning boom 15 is fastened via support parts 17 to a support boom 18 which, as is known, for example, from EP-PS 0109472 (T 613), is rotatably mounted on the machine frame and can be clamped counterclockwise in FIG. 2 via a torsion spring bar (not shown). Correspondingly, the tensioning boom 15, which can be pivoted about the axis of the support boom 18, is resiliently braced against the warp threads 10, the tension of the partial chains 11 and 12 being absorbed by the twisted spring bar. On the deflection element 14, two sensing elements 21 and 22, each associated with one of the partial chains 11 and 12, of a device (not shown further) for detecting the tension of the warp threads 10 are fastened via resilient holders 20. As is known from the aforementioned EP-PS 0136389, a number, z. B. hundred, warp threads 10 out. The sensing elements 21 and 22 cooperate with sensors (not shown), each of which transmits a control signal corresponding to the tension of the warp threads 10 of the partial chain 11 or 12 to a common control device 25 via a signal line 23 or 24. According to the illustration in FIG. 1, an additional sensor 26 can be provided at one end of the support tree 18 for detecting a supporting force determined from the sum of the warp tension forces of the partial chains 11 and 12, from which a signal line 27 a control signal corresponding to this supporting force can be transmitted to the control device 25.

According to the illustration, each of the partial warp beams 1 and 2 is also assigned a measuring device 31 or 32, which is intended to detect the length of a length section of the warp threads 10 that runs from the relevant partial warp beam 1 or 2 during a warp thread feed. The measuring devices 31 and 32 are each connected to a signal line 33 or 34, via which a control signal corresponding to the length segment of the partial chain 11 or 12 running from the partial warp beam 1 or 2 can be transmitted to the control device 25. The control device 25 is connected via control lines 35 and 36 to the drive motors 6 and 7, respectively, via which the warp let-off speed of the sub-warp beams 1 and 2, depending on a predetermined combination of the control signals obtained from the sensing elements 21 and 22 and the sensor 26 and from of the control devices 31 and 32 received control signals is set.

1 and 2, the measuring devices 31 and 32 can each contain a measuring roller 37 which is rotatably mounted on a holder 38 which can be moved against the circumference of the partial warp beam 1 or 2 and away therefrom. The brackets 38 can each be pivotably articulated on a fixed supporting part, as shown in the illustration a console 40 attached to the deflection element 14, between the position shown in full lines and a position 38 'shown in broken lines and under the action of a spring 41 against the circumference of the part warp beam 1 or 2 can be held clamped. Correspondingly, the measuring roller 37, following the decreasing winding diameter, is constantly pressed against the circumference of the wound partial warp beam 1 or 2 and set in rotation by this by an angle corresponding to the respective warp thread feed. By means of a sensor 42 assigned to the measuring roller 37, a control signal corresponding to the respective angle of rotation can be transmitted to the control device 25 via the signal line 33 or 34.

Corresponding measuring devices 31 and 32 can also be arranged at a distance from the partial warp beams 1 and 2, according to FIG. 3, in the region of the section 10a of the warp threads 10 which runs between the deflection element 14 and the tensioning beam 15. According to the illustration, the measuring rollers 37 can each be mounted on a holder 43 which is accessible from the warp side of the weaving machine and which is held on a stationary support part 44, for example under the action of a spring element 45 shown as a compression spring, against the warp threads 10 running via a support roller 46 . As shown, the support rollers 46 can each be mounted on a bracket 47 attached to the deflection element 14. Instead of a rotatable support roller, another guide element, for. B. a support plate may be provided. This embodiment has, in addition to the advantage of the arrangement of the measuring devices 31 and 32 accessible from the warp side, the additional advantage that the length of the length section of the warp threads 10 corresponding to the respective warp thread feed in a defined area of the deflected element at the deflection element 14 Warp thread course is detected in which all the warp threads 10 have essentially the same warp thread tension that is independent of the respective winding condition of the partial warp beam 1 or 2. Accordingly, it can be ensured that the warp thread feed detected in the measuring area matches the actual feed of the entire part chain 11 or 12.

4, the measuring rollers 37 can also each be arranged on a rod-like holder 48, which is guided in a stationary guide part 50, essentially radially to the axis of the partial warp beam 1 or 2, and between the position shown in full lines and one Position 48 'shown in dashed lines is held displaceably. The measuring roller 37 can be pressed against the circumference of the wound partial warp beam 1 or 2 under the effect of the dead weight of the holder 48 or under the effect of a spring (not shown). As from Fig.4 further emerges, the warp threads 10 of the partial warp beam 1 or 2 can also be guided directly against the tensioning beam 15, which in the illustrated embodiment can be supported in spring-mounted, lateral bearings, each of which is known per se, not shown Both ends of the spanning tree 15 can be assigned a sensor intended to detect the supporting force, for example corresponding to the sensor 26 in FIG. 1, by means of which a control signal corresponding to the respective supporting force and thus the respective distribution of the warp tension forces can be transmitted to the control device 25.

An embodiment is also possible in which the spanning tree is mounted in bearings which are provided with corresponding sensors and are arranged in a fixed position. Instead of a spanning tree that extends across the entire weaving width, sub-spanning trees subdivided can also be provided analogously to the assigned part warp beams 1 and 2.

Via the control device 25, the drive motors 7 and 8 can be controlled in accordance with the control signals of the sensors 21, 22 and 26 which detect the tension of the warp threads 10 and the measuring devices 31 and 32 which detect the running length of the warp threads 10 in such a way that those of the partial warp beams 1 and 2 running part chains 11 and 12 each have the same running speed. The control lines 33 and 34 of the measuring devices 31 and 32 can be connected to the control device 25, for example via a control unit 30 indicated in FIG. 1, through which the control signals of the sensors 21, 22 and 26 on the one hand and the control signals of the measuring devices 31 and 32, on the other hand, are weighted in a predetermined ratio - for example 40% depending on the tension and 60% depending on the running length of the warp threads 10 - for controlling the warp let-off device.

The proportions of these control signals can each be adjustable between 0 and 100%. For example, when processing partial warp beams 1 and 2 with the same winding diameters, the length of the respective warp thread feed can be dispensed with and the warp let-off devices can be controlled exclusively as a function of the sensors 21, 22 and 26 that detect the tension of the warp threads 10. Conversely, in particular when processing partial warp beams 1 and 2 with different winding diameters, the detection of the warp thread tensions can be dispensed with or the processing of the corresponding control signals can be dispensed with, so that the drive motors 7 and 8 exclusively as a function of the control signals of the measuring devices 31 and 32 can be controlled.

It goes without saying that any combination of the proportions of these control signals can be set via the control device 25 or the control unit 30 and used for controlling the warp let-off devices. For example, when setting the weaving machine, the weighting between warp thread tension and warp thread consumption that is most advantageous for the fabric quality is selected, e.g. for the processing of warp threads 10 of low elasticity, a correspondingly predominant proportion of the signals detecting the warp thread consumption, and for the processing of warp threads 10 of higher elasticity, a corresponding predominant proportion of the control signals detecting the warp thread tension can be taken into account.

abgeleitet und damit die Länge s des jeweiligen Kettfadenvorschubs entsprechend der Beziehung

$\text{s = v . T}$

ermittelt werden. Als Sensoren können kapazitive, optische oder Piezo-Elemente verwendet werden.Instead of the mechanical measuring devices 31 and 32, corresponding measuring devices 51 intended for direct measurement of the warp thread feed can also be provided according to FIG. 5, which each contain two sensors 52 and 53 which are located one behind the other at a distance A in the running direction (arrow 13) of the warp threads 10 each respond to the structure of the continuous warp thread 10 or a group of the continuous warp threads 10 and thus generate two signals which are determined by the thread structure and are similar to one another. 6 is in the diagram the time course of two corresponding control signals C₅₂ and C₅₃ shown, which follow one another in a time period corresponding to the warp thread feed T and which are transmitted via signal lines 34a and 34b to the control device 25 and can be compared, for example by correlation methods. From this time shift of the two signals, the speed v of the warp thread 10 running between the sensors 52 and 53 can be determined according to the relationship

$\text{v = A / T}$

derived and thus the length s of the respective warp feed according to the relationship

$\text{s = v. T}$

be determined. Capacitive, optical or piezo elements can be used as sensors.

Instead of the sensors 52 and 53 described above, other types, e.g. UV sensors can be provided, each of which responds to markings made on the relevant warp thread 10 or on a warp thread group, for example in the form of a color print. The length measuring devices 31, 32, 51 and the corresponding control unit 30 provided according to the invention can also be attached to an existing weaving machine and connected to the existing control device for the warp let-down which can be influenced as a function of the warp thread tension.

The design of the weaving machine according to the invention is also possible for designs with partial warp beams arranged parallel to one another and / or with more than two, e.g. three or four, partial warp beams applicable, each of which can be assigned one of the length measuring devices described above.

Claims (7)

Loom with at least two partial warp beams (1, 2) and a tensioning beam (15) for guiding warp threads (10) running from the partial warp beams (1, 2), each of the partial warp beams (1, 2) being coupled to an individually controllable warp let-off device and Sensing elements (21, 22, 26) for detecting the tension of the warp threads (10) and a control device (25) for individually adjusting the speed of the part warp beams (1, 2) are provided, characterized in that each of the part warp beams (1, 2) a measuring device (31, 32; 51) for detecting the length of a length section of at least part of the warp threads (10, 2) running from the relevant partial warp beam (1, 2) running along this measuring device (31, 32; 51) is assigned and that a control signal corresponding to the relevant length section can be transmitted to the control device (25) via this measuring device (31, 32; 51), via which the rotational speed of the Te ilkettbaums (1 or 2) depending on this control signal in the sense of keeping a predetermined length of this length section constant. Weaving machine according to claim 1, characterized in that the measuring device (31, 32) is arranged on a holder (38) which can be braced against the circumference of the partial warp beam (1, 2) wound with the warp threads (10) and can be moved away therefrom. Weaving machine according to claim 1, characterized in that the measuring device (31, 32; 51) is arranged at a distance from the partial warp beam (1, 2), in the region of a section (10a) of the warp threads (10) running from it. Weaving machine according to one of the preceding claims, characterized in that the measuring device (31, 32) contains a measuring roller (37) which can be pressed onto a number of warp threads (10) and can be driven to rotate therewith and which has a sensor (42) for detecting its respective one Warp thread feed corresponding rotation angle is connected to the control device (25). Loom according to claim 3 or 4, characterized in that the measuring device (31, 32) is arranged in the region of a stationary guide element (46) for at least part of the warp threads (10). Loom according to claim 1 or 3, characterized in that the measuring device (51) contains two sensors (52, 53) arranged one behind the other at a predetermined distance (A) in the running direction (13) of the warp threads (10), by means of which two each by the Structure of at least one of the warp threads (10) determined, offset by a time period (T) corresponding to the warp let-off speed, mutually similar control signals (c₅₂, C₅₃) can be transmitted to the control device (25). Loom according to one of the preceding claims, with sensing elements (21, 22, 26), via which a control signal corresponding to the respective warp thread tension can be transmitted to the control device (25), characterized in that the control device (25) contains a control unit (30) , by means of which the control signals corresponding to the respectively detected warp thread tension and the control signals corresponding to the respectively detected length section of the warp threads (10) can be transmitted to the warp let-off device in a predetermined ratio, the proportions of these control signals each being adjustable between 0 and 100%.

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